Organometallic compounds



United States Patent Ofilice 3,042,693 Patented July 3, 1962 This invention relates to novel organometallic compounds and more particularly to aromatic compounds of manganese. In addition, the present invention relates to manufacture and use of the above compounds.

It is an object of this invention to provide a new class of organometallic compounds. More particularly, it is an object to provide new compounds of manganese which are relatively stable and which are soluble in organic media, particularly hydrocarbons. Another object is to provide compounds of the above type which are useful as antiknocks in gasoline used for internal combustion engines. Still another object is to provide a novel process for manufacture of such compounds and fuel compositions containing the same. Other objects and advantages of this invention will be more apparent from the following description and appended claims.

The above and other objects of this invention are accomplished by the provision of a novel class of compounds having an aromatic molecule coordinated with a manganese atom, the compound being stabilized by additional coordination with two carbonyl groups and a cyano group, the aromatic molecule contributing six electrons, the carbonyl groups each contributing two electrons and the cyano group contributing one electron to the manganese, thereby giving the manganese a total of eleven additional electrons and resulting in the manganese atom having the configuration of krypton. More specifically, the aromatic cyano manganese dicarbonyl compounds of this invention have the general formula wherein A is an aromatic molecule.

The compounds of this invention are unexpectedly stable to light, heat and other influences. As such, these compounds are very useful in many applications wherein stability is an important factor. The compounds are also coordination complexes and thus are soluble in organic media, particularly of the hydrocarbon type. These compounds are also antiknocks and, in use, are preferably injected into internal combustion engines as a component of the fuel mixture.

Typical examples of compounds of this invention are benzene cyanomanganese dicarbonyl, toluene cyanomanganese dicarbonyl, o-xylene cyanomanganese dicarbonyl, p-xylene cyanomanganese dicarbonyl, mesitylene cyanomanganese dicarbonyl, diphenyl cyanomanganese dicarbonyl, tetralin cyanomanganese dicarbonyl, ethylbenzene cyanomanganese dicarbonyl, n-octyl benzene cyanomanganese dicarbonyl, and the like.

The aromatic compounds coordinated to the metal in the compounds of this invention which are represented by A in the above formula arein general compounds preferably containing an isolated benzene nucleus. That is, aromatic compounds which are free of aliphatic unsaturation on a carbon atom adjacent the benzene ring and which do not contain unsaturation on a carbon atom of a fused ring which is adjacent the benzene nucleus. That is, the aromatic compounds which are preferred for this invention have no aliphatic double bond in conjugated relationship to the ring. Thus, aryl and alkyl substituted aromatic compounds are also preferred as are fused ring compounds having isolated benzene nuclei, that is, having no unsaturation on a carbon atom adjacent to a benzene ring. .Aro-

matic compoundshaving from 6 to 18 carbon atoms are generally preferred in compounds of this invention. Benzene itself, mesitylene, toluene, biphenyl, tetralin, mhexylbiphenyl, and the like are examples of applicable aromatic compounds.

Typical examples of other compounds which are also suitable and which do not have an isolated benzene nucleus are styrene cyanomanganese dicarbonyl, methylstyrene cyanomanganese dicarbonyl, naphthalene cyanomanga nese dicarbonyl, and the like.

The compounds of this invention can be prepared by a number of techniques. One typical method is to form the desired compound by decarbonylating the corresponding aromatic metal tricarbonyl cyanide by pyrolysis in accordance with the following equation wherein'A is an aromatic molecule as defined above. This pyrolysis can be conducted at a temperature of between about 20" and 300 C., but is usually carried out between about 50 and 200 C. Likewise, while not essential, the reaction is best conducted in an inert liquid medium and preferably in a solvent forthe tricarbonyl reactant but which is not a solvent for the product. For this reason, polar solvents are frequently preferred.

The pyrolysis to form the aromatic cyanomanganese dicarbonyl can be accomplished simultaneously with the formation of the aromatic manganese tricarbonyl cyanide reactant. For example, a typical method for producing the aromatic manganese tricarbonyl cyanide involves the reaction of an aromatic manganese tricarbonyl halide with an active cyanide compound. This reaction can be conducted at temperatures defined above for pyrolysis, i.e., 20-300 C., to simultaneously produce the compounds of this invention. Likewise, the aromatic manganese tricarbonyl halide does not require isolation prior to conversion to the compounds of the present invention.

A typical series of reactions which can be conducted to form the aromatic manganese tricarbonyl cyanide reactant is as follows:

wherein X is a halogen, M is a metal and m is the valence of the metal M. Thus, the above reactions can be conducted separately and, in each instance, the desired intermediate separated and isolated. Alternatively, the reactions can be conducted simultaneously or sequentially without separation of products.

The halogenation of the manganese pentacarbonyl (2) can be conducted over a wide temperature range such, for example, as 70 to C. although the reaction is preferably conducted at a temperature of 0 to 50 C. The reaction is preferably conducted in an inert liquid, preferably one which is a solvent for the manganese pentacarbonyl, for example, chlorinated hydrocarbons such as ethyl chloride and carbon tetrachloride, and the like; aliphatic hydrocarbons such as pentane and hexane; aromatic solvents such as benzene, toluene and xylene; solvents such as carbon disulfide and organic acids such as an acetic acid. The concentration of solvent is not critical as long as there is enough to provide solubility for manganese carbonyl.

Any of the halides are suitable in this reaction such as, for example, the chlorides, bromides, iodides or fluorides.

The reaction of the aromatic compound with the halogen manganese pentacarbonyl (3) is generally catalyzed by a Friedel-Crafts catalyst and is normally conducted v weight.

I at a. temperature of from about 20 to 300 C. A more Bya Friedel-Crafts catalyst is meant a. salt having elec-' trophilic characteristics. These are. usually" halides of metals of groups IIA, IIB, HIA, IVB VB, VI-B, VIIB and VIII of the periodic table. The preferred halides are halides of groups lIIA, IVB and V IH. Illustrative examples of preferred metal halides'are boron tn'fluoride, boron trichloride, boron tribromide, boron triiodide, aluminum trichloride, aluminum trifluoride, titanium tetrachloride, titanium tetrabromide, ferric chloride, and the like. Also in many instances,it is desirable to employ the corresponding hydrohalide along with the metal halide, e.g. a -boron trichloride-hydrogen chloride catalyst system. Other examples of suitable Friedel-Crafts catalysts of generally lesser activity are .zinc, gallium, indium, thallium, beryllium, magnesium, zirconium, vanadium,

.chromium, manganese and cobalthalides.

benzene manganese .tricarbonyl, the react-ion is conducted in .a benzenem'edium- The reaction can. also be conducted in a halogenated benzene such as'chlorobenzene or bromoben'zene, inwhich event the chloroaromatic or 4 e manganese dicarbonyl was 170172 C. Chemical analysis of the product was as follows:

Found Calculated Carbon 55. 8 56. 0 Hydrogen 4. 79 4. 65 Nitrogen 5. 45 5. 45

An infrared spectrum confirmed the structure of this product. The product obtained in this example is an effective antiknock when used in fuels for internal combustion engines.

Example II Mesitylene manganese tricarbonyl iodide (3.86 parts) 7 was reacted with 2 parts of potassium cyanide, but in this bromoaromatic manganese .tricarbonyl-halide .is formed.

Other substituted aromatic compounds can be produced in like manner. a a

In addition to the aromatic compound, other solvents or x diluents can be employed. Typical examples of such dicarbonyl cyanide. In this process, any active cyanide compound can be used but the cyanides of metals of groups I to III of the periodic table are preferred. Best results are obtained with the alkali metal compounds, such as sodium cyanide, potassium cyanide and lithium cyanide. compounds are calcium cyanide, magnesium aluminum cyanide. l V I Any of a wide variety of solvents can-be employed in Step 4, particularly polar solvents. Water, lower aliphatic alcohols .and others such as acetone are preferred. The alcohols havingalkyl groups containing} to 6 carbon atoms give excellent results. The concentration of soi vent isnot critical. Quantities of from about 0.I part to cyanide and about 100 parts per part of reactant can be used, although from about 1 to 10 parts are preferred.

. Mesi tylene manganese 'tricarbonyl iodide, (3.86" parts) was dissolved in 100 parts of hot water and, while boiling,

Example III Twenty five parts of bromomanganese pentacarbonyl,

10 parts of aluminum chloride and 108 parts of mesitylene were refluxedunder nitrogen until the gas evolution P had terminated. After cooling the reaction mixture, the

mesitylene manganese tricarbonyl bromide was hydrolyzed 'with 100 parts of water. The water layer was thereafter separated and treated with excess'potassium cyanide; A'green precipitate was formed. Thereafter sufficient sodium hydroxide (5 percent solution) was added to the reaction product to raise the pH to 8.5, under which conditions the color of the solution changed to yellow. The product'was then extracted with water and the extract was concentrated whereupon yellow crys- Other typical examples of suitable metal cyanide 3 parts of potassium cyanidewere added. Mesitylene' cyanomanganese' dicarbonyl, a yellow precipitate, was formeddirectly,'carbon monoxide being evolved in about one mole equivalent quantities. The reaction mixture was cooled and filtered and 2.26 partsof mesitylene cyanomanganese dicarbonyl product was obtained. This product was recrystallized in water three, times, washed with a.

small amount of diethyl ether and dried under reduced tained.

tals of mesitylene cyanomanganese dicarbonyl were obtained. This product was thereafter recrystallized from water giving6.1 2 parts of mesitylene'cyanomanganese dicarbonyl. The productwas identified by infrared analy- SIS. r

'When the aboveexample is carried out in using other Friedel-Crafts catalyst such as boron trifluoride, boron trichloride-HCI and ferric'chloride' similar resultsare ob- Example IV Example I is repeated except that benzene manganese tricarbonyl bromide is reacted with sodium cyanide in 15 0 parts of ethyl alcohol. The solution isrefluxed until gas evolution ceases. Similar results are obtained except that the product is benzene cyanomanganese dicarbonyl.

Example V 7 Example I is repeated using xylene manganese tricarbonyl chloride in ethylene glycol solvent to produce xylene cyanomanganese dicarbonyl. The pyrolysisreaction is conducted at: C. untilall of the freed carbon monoxide has been evolved.

Example VI Tetralin manganese tricarbonyl iodide (4.4 parts) is dissolved in parts of water, This solution is heated to a temperature of50 C. and 3.2 parts of calcium cyanide is added over a period of 10 minutes. The heating is continued withstirring until there is no evidence of furpressure The melting point of the mesitylene cyano- 75 ther gas evolution. The product reaction mass is then cooled to room temperature and the tetralin cyanomanganese dicarbonyl purified as in Example 1.

Example VII Ethylbenzene manganese tricarbonyl cyanide is heated in dioxane to a temperature of 100 C. The solution is maintained at this temperature until the gas evolution ceased. The reaction mixture is then cooled to room temperature and the product ethylbenzene cyanomanganese dicarbonyl is recovered in accordance with the preceding examples.

Example VIII Triethylbenzene manganese tricarbonyl chloride (8.3 parts) is dissolved in 250 parts of acetone. The solution is heated to a rolling boil and 5 parts of lithium cyanide is added to the solution. Carbon monoxide gas is evolved and the solution is maintained at reflux until no additional gas evolution is apparent. The triethylbenzene cyanomanganese dicarbonyl is recrystallized from triethanol amine and subsequently recrystallized twice in water. The crystals are washed with a small amount of dimethyl ether and dried at reduced pressure.

Example IX Fifty parts of bromomanganese pentacarbonyl, 18 parts of aluminum bromide and 200 parts of n-cctylbenzene are refluxed in an inert atmosphere until gas evolution has ceased. After cooling the reaction mixture, the product is hydrolyzed with 150 parts of water. The water layer is separated and 4 parts of sodium cyanide is added to this solution. Suflicient potassium hydroxide percent solution) is added to the reaction product to raise the pH of the solution to 8.0. The product, n-octylbenzene cyanornanganese dicarbonyl, is thereafter recovered in accordance with the procedure of Example III.

The compounds of this invention can be employed with hydrocarbon fuels and lubricating oils for improving operating characteristics of spark ignition internal combustion engines. The compounds can be used in fuels and lubricating oils by themselves or together with other additive components, such as scavengers, deposit modifying agents containing phosphorus and/or boron, and also other antiknock agents, such as tetraethyllead, etc. When an aromatic cyanomanganese dicarbonyl compound is added to gasoline, a substantial increase in the octane value of the fuel results.

The compounds can be added directly to the hydrocarbon fuels or lubricating oils and the mixture'subjected to stirring, mixing, or other means of agitation until a homogeneous fluid results. Alternatively, the compounds of our invention may be first made up into concentrated fluids containing solvents, such as kerosene, toluene, hexane, and the like, as well as other additives such as scavengers, antioxidants and other antiknock agents, e.g., tetraethyllead. The concentrated fluids can then be added to the fuels.

As the organo lead antiknock agent which is an ingredient of certain of the compositions of this invention, organolead compounds in general may be used. Preferable, however, are hydrocarbon lead compounds such as tetraphenyllead, tetratolyllead, and particularly tetraalkyllead compounds such as tetramethyllead, tetrapropyllead and the like. In general the amount of organolead antiknock agent is selected so that its content in the finished gasoline is equivalent to at least about 1 gram of lead per gallon.

Where halohydrocarbon compounds are employed as scavenging agents, the amounts of halogen used are given in terms of theories of halogen. A theory of halogen is defined as the amount of halogen which is necessary to react completely with the metal present in the antiknock mixture to convert it to the metal dihalide as, for example, lead dihalide and manganese dihalide. In other 6 I words, a theory of halogen represents two atoms of halogen for every atom of lead and/or manganese present. In like manner, a theory of phosphorus is the amount of phosphorus required to convert the lead present to lead orthophosphate, Pb (PO that is, a theory of phosphorus based on lead represents an atom ratio of two atoms of phosphorus to three atoms of lead. When based on manganese, a theory of phosphorus likewise represents two atoms of phosphorus for every three atoms of manganese, that is, suflicient phosphorus to convert manganese to manganese orthophosphate, Mn (PO When employing the compounds of this invention together with scavengers, an antiknock fluid for addition to hydrocarbon fuels is prepared comprising aromatic cyanomanganese dicarbonyl compounds together with various halogen-containing organic compounds having from 2 to about 20 carbon atoms in such relative proportions that the atom ratio of manganese-to-halogen is from about 50:1 to about 1:12. The scavenger compounds can be halohydrocarbons both aliphatic and aromatic in nature, .or a combination of the two, with linegens being attached to carbons either in the aliphatic or the aromatic portions of the molecule. The scavenger compounds may also be carbon, hydrogen, and oxygencontaining compounds, such as haloalkyl others, halohydrins, halo esters, halonitro compounds, and the like. Still other examples of scavengers that may be used in conjunction with our manganese compounds either with or without hydrocarbolead compounds are illustrated in U.S. Patents 2,398,281, 2,479,900, 2,479,901, 2,479,902, and 2,479,903, and the like. Mixtures of different scavengers may also be used. These fluids'can contain other components as stated hereinabove. In like manner, manganese-containing fluids are prepared containing from 0.01 to 1.5 theories of phosphorus in the form of phosphorus compounds. To make up the finished fuels, the concentrated fluids are added to the hydrocarbon fuel in the desired amounts and the homogeneous fluid obtained by mixing, agitation, etc.

The ratio of the weight of manganese to lead in fluids and fuels containing the two components can vary from about 1:880 to about 50:1. When no lead is present, the latter figure becomes 1:0. A preferred range of ratios, however, when both the manganese compounds of this invention and hydrocarbolead compounds are employed, is from about 1:63 to about 30:1.

The following examples are illustrative of fluids and fuels containing our new compounds.

Example X To 1000 gallons of a commercial fuel having an initial boiling point of F. and a final boiling point of 406 F. is added 55 grams of benzene cyanomanganese dicarbonyl, and the mixture subjected to agitation until the additive is distributedevenly throughout the fuel, in an amount equivalent to 0.013 gram of manganese per gallon of fuel.

Similar results are obtained with other aromatic cyanornanganese dicarbonyls such as xylene cyanomanganese dicarbonyl, mesitylene cyauomanganese dicarbonyl, and the like.

. Fuels containing mixtures of two or more aromatic cyanornanganese dicarbonyls, such as the mixture of benzene cyanomauganese dicarbonyl and xylene cyanomanganese dicarbonyl are prepared in a manner similar to that employed in the above example.

Example X] To 10 parts of benzene cyanomanganese dicarbonyl is added 5 parts of ethylene dichloride and the mixture agitated until a homogeneous fluid results. The manganese to chloride atom ratio in this fluid is 1:12 and represents 6 theories of halogen based on the manganese. This fluid is added to hydrocarbon fuels in amounts so as to pro- 16 grams and 10 grams of manganese per gallon.

Example XII To 13.2 parts of lead in the form of tetraethyllead in an antiknock fluid containing 0.5 theory of bromine as ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride, wherein the theories of halogen are based upon the amount of lead present, is added 0.015

part of manganese in the form of mesitylene cyano-man- To a fuel containing 0.02 gram of lead per gallon as 7 diphenyldiethyllead, 1.0 theory of bromine as ethylene dibromide, and 0.2 theory of phosphorus in the form of tricresyl phosphate, is added mesitylene cyanomanganese 'dicarbonyl in an amount equivalent to 0.03 gram of manganese per gallon. This small amount of manganese in the, form of the compounds of this invention provides aconsiderable increase in the'antiknock quality of the fuel as shown upon testing in a single-cylinder engine.

Otherfuels and fluids areprepared in thersame man- 'her as illustrated hereinabove which contain other depositrnodifying agents, such as boric acid, borate esters, boronic esters, etc. Likewise, lubricating oils containing from about 0.1 to about weight percent manganese in the form of the aromatic cyanomanganese dicarbonyl compounds of this invenion are prepared, and these lubricating oils, when used in reciprocating engines, are found to have a beneficial effect on engine cleanliness and in the reduction of combustion chamber deposits. 7

The fuels to which the antiknock compositions of this invention are-added may have a wide variation of compositions. These fuels generally are petroleum hydrocarbons and are usually blends of two'or more components. These fuels can'contain all types of hydrocarbons, including parafiins, both straight and branched chain; olefins; cycloaliphatics containing paraflin or. olefin side chains; and aromatics containing aliphatic side chains. The fueltype depends on the base stock'from which it is obtained and on the method of refining. For example, it can be a straight run or processed hydrocarbons, including thermally cracked, catalytically cracked, reformed fractions, etc. gines, the boiling range of the components of gasoline can vary from zero to about 430* F., although the boiling range of the fuel blend is often found to be between an initial boiling point'of from about 80 F. to 100 F.

r and a final boiling point of about 430 F. While the temperatures.

The'amount of manganese that can be employed in the 7 form of aromatic cyanomanganese dicarbonyl compounds of this invention in hydrocarbon fuels of the gasoline boiling range can vary from. about 0.015 to about 1.0 :grams of manganese per gallon, preferably 0.03 to v6 grams of manganese per gallon. In addition, the fuel can also contain organolead antiknock agents such as tetraethyllead in amount equivalent to from about 0.02 to about 13.2 grams of lead per gallon; 7 V

I The aromatic cyanomanganese dicar-bonyl compounds of this invention may be incorporated in paints, varnish, printing inks, synthetic resins of the drying oil type, oil enamels and the like, to impart excellent drying characteristics to such compositions. Generally speaking,

When used for spark-fired enfrom 0.01 to'0.05 percent of manganese as a compound of this invention is beneficially employed as a dryer in such a composition. a

For example, to a typical varnish composition containing parts ester gum, 173 parts, of tung oil, 23 parts of linseed oil and 275 parts of white petroleum naphtha is added 3.0 parts of mesitylene cyanomanganese dicarbonyl. The resulting varnish composition is found to have excellent drying characteristics. Equallygood results are obtained when other drying oil compositions and other aromatic cyanornanganese dicarbonyl compounds of this invention are employed.

Other important usesof the aromatic cyanoman-ganese dicarbonyl compounds of'the present invention include the use thereof as chemical intermediates, particularly in the preparation of 'metal and metalloid containing polymeric materials. In addition, some of the aromatic derivatives of this invention can be used in the manufacture of medicinals and other therapeutic materials, as 'well as cule coordinated with manganese, the compound being stabilized by additional coordination with two carbonyl groups and a cyano group, the aromatic hydrocarbon molecule contributing six electrons, thecarbonyl groups each contributing two electrons and the cyano group contributing one electron to the manganese, thereby giving the manganese a total of eleven additional electrons and resulting in the manganese atom having the electron configuration of krypton.

2.. The process for producing compounds having an aromatic hydrocarbon molecule coordinated with manganese, the compound being stabilized by additional coordination with two carbonyl groups and a cyano group, the aromatic hydrocarbon molecule contributing six electrons, the carbonyl groups each contributing two electrons and the cyano group contributing one electron to the manganese, thereby giving the manganese a total of eleven additional electrons and resulting in the manganese atom having the electron configuration of krypton, comprising decarbonylating an aromatic hydrocarbon manganese tricarbonyl cyanide by heating to a temperature of 20- 300 C. a t

3. Mesitylene cyanomanganese dicarbonyl.

4. The process of claim 2 wherein:

(1) the compound produced is'mesitylene' cyanomani ganese dicarbonyl; and V (2) Thearomatic hydrocarbon manganese tricarbonyl cyanide reactant is mesitylene manganese tricarbonyl cyanide. i 7

*References Cited in the file of this patent UNITED STATES PATENTS Brown et al Dec. 31, 1958 OTHER REFERENCES Piper et al.: .1. Inorganic and Nuclear Chem, 1955, vol. 1, pp. -174 '(pp. 167-168 relied on).

Brook: I.A.C.S. 77, 4827-4829 (1955).

Fischer: Chemistry and Industry, pp. 153-154, Mar. 

1. A COMPOUND HAVING AN AROMATIC HYDROCARBON MOLECULE COORDINATED WITH MANGENESE, THE COMPOUNBD BEING STABILIZED BY ADDITIONAL COORDIANTION WITH TWO CARBONYL GROUPS AND A CYANO GROUP, THE AROMATIC HYDROCARBON MOLECULE CONTRIBUTING SIX ELECTRONS, THE CARBONYL GROUPS EACH CONTRIBUTING TWO ELECTRONS AND THE CYANO GROUP CONTRIBUTING ONE ELECTRON TO THE MANGANESE, THEREBY GIVING THE MANGANESE A TOTAL OF ELEVEN ADDITIONAL ELECTRONS AND RESULTING IN THE MANGANESE ATOM HAVING THE ELECTRON CONFIGURATION OF KRYPTON. 